Pregnancy Week 21: Your Baby's Moves and Your Midwife Appointments

Quick answer: At 21 weeks your baby weighs around 360 grams and measures about 26.7cm from crown to heel, and their movements should now be regular. There is no set number of movements to feel each day, so learn your baby's own pattern and contact your midwife immediately if movements reduce or change. If this is your first pregnancy, your next routine appointments are usually around 25 and 28 weeks.

What parents need to know

Week 21 brings you further into the heart of the second trimester. Your baby's movements are becoming more regular and distinctive, and you're settling into a rhythm of antenatal appointments that will continue throughout your pregnancy. This week is a good time to think about your birth plan and preferences for your baby's arrival.

How big is your baby at 21 weeks?

Your baby now weighs approximately 360 grams and measures around 26.7cm from crown to heel — roughly the size of a carrot. They're becoming more and more of a real, individual presence.

What's happening with your baby?

Your baby's eyebrows and eyelids are now fully formed. Their lips are becoming more defined. The digestive system continues to practise, with your baby swallowing amniotic fluid regularly. The pancreas, which will eventually produce insulin and digestive enzymes, is steadily developing.

Your baby's sleep cycles are becoming more established, and you may notice periods of activity followed by periods of quiet. Many babies are most active when their mother is still, as movement during the day can lull them to sleep. So if you notice increased movement at night when you're trying to sleep, this is perfectly normal.

Your baby may also be responding to sounds from outside the womb. Loud, sudden noises can cause a startle response. Playing music, talking, and reading aloud are all wonderful ways to bond with your baby during pregnancy.

Monitoring baby's movements

By week 21, you should be noticing regular movements from your baby. There is no set number of movements you should feel each day — every baby has their own normal pattern. The important thing is to get to know what's normal for your baby, and to contact your midwife immediately if you notice a reduction in movements or a change in your baby's usual pattern. Never wait until the next day to report reduced movements. Contact your midwife unit or call NHS 111 if your maternity unit is closed.

From 28 weeks onwards, the NHS places greater emphasis on monitoring movements, but beginning to tune in to your baby's patterns now gives you a useful baseline.

Planning for the birth: beginning to think about your preferences

It's not too early to start thinking about your birth preferences, even if a formal birth plan feels like something for later in pregnancy. Some questions worth reflecting on include: Where would you like to give birth? (Options typically include a hospital obstetric unit, a midwife-led unit, or a home birth.) Who would you like as your birth partner(s)? What are your thoughts on pain relief options? Are there any cultural or personal preferences that are important to you?

Your midwife will discuss birth preferences with you at a later appointment, usually around 34 to 36 weeks, and will help you record them. The NCT has excellent resources to help you think through your options.

Antenatal appointments in the second trimester

If this is your first pregnancy, your next routine appointments after the 20-week scan will typically be at around 25 and 28 weeks. At 28 weeks, you will be offered another blood test to check for anaemia and to recheck your blood group. Women who are Rhesus negative will be offered anti-D injections at around 28 weeks to prevent complications in this or future pregnancies.

Your week 21 checklist

This week:

• Start tuning in to your baby's movement pattern.
• Begin thinking about birth preferences.
• Look into local birth options (hospital, midwife-led unit, home birth).
• Continue regular exercise and pelvic floor exercises.
• Contact your midwife without hesitation if you notice any reduction in movements.

Frequently asked questions

How many movements should I feel at 21 weeks?

There is no set number of movements to feel each day. Every baby has their own pattern, so the aim is to learn what is normal for your baby and use it as a baseline.

What should I do if my baby's movements reduce?

Contact your midwife immediately if movements reduce or your baby's usual pattern changes. Never wait until the next day. Call your maternity unit, or NHS 111 if the unit is closed.

Why is my baby more active at night?

Many babies are most active when their mother is still, because daytime movement can lull them to sleep. Increased movement at night when you are trying to sleep is perfectly normal.

When will I discuss my birth plan with my midwife?

Your midwife will discuss your birth preferences with you at a later appointment, usually around 34 to 36 weeks, and will help you record them.